The proposed research is a comprehensive, 36 month, synthetic and biological testing program aimed at the development of novel non-steroidal male contraceptive agents that will immobilize spermatozoa and that are related to ketoconazole, itraconazole and terconazole. The proposed research may lead to the development of new derivatives of ketoconazole, itraconazole and terconazole providing new, highly effective, and safe male contraceptive agents.